Back in March I posted a problem I was having with what appeared to be the Knock sensor. It was a HUGE pain in the butt and continues to be to this day. However...I took my 2002 Xterra to a semi-local guy who has been repairing foreign engines for a long time and now know the REAL problem. Unfortunately it's gonna be $720 to fix! He told me the AIR FLOW METER was shot.

Has anyone else had experiences with this problem? (I still say Wal Mart screwed it up!)

WTF is an air flow meter? What was the origional problem with your X?

The MAF (mass air flow) sensor was bad? Is that what you mean by air flow meter?
How does that:
a: cause engine knock?
b: cost $720?

On another car, after changing the air filter out, I forgot plug the MAF sensor back in. Engine ran like crap except at WOT. Didn't knock though.

What year is your Xterra? Because a lot of people go through knock sensors like crazy on first gens.


BTW: I don't know how Wal-Mart screwed up the MAF, but you're lucky if that's all they screwed up. I used to work at a Wal-Mart, and I was one of the manager's go to guys when special problems popped up. I can't count the times I had to drive to someone's house to replace the oil filler cap the techs forgot to put back in along with oil to replace what sprayed out and degreaser to clean the car.
The store replaced several people's engines b/c of that. Or the techs cross threaded oil pan plugs, installed tires without balancing them, etc. I will never take my vehicle to Wal-Mart unless I personally know the tech that is gonna work on my vehicle.

If it's the MAF try cleaning it.

where is the
MAF located.

On the intake, between the air filter box and the intake plenum.


http://xterrafirma.com/albums/TJs-X-Winch-Stuff/OEM_Radiator_Fan_Areas_D_side_view.jpg

Look to the bottom, Right corner of the pic.


:D

is it the RED plug?

yeah, it's the red plug

yup, red plug

Buy some MAF cleaner at your local auto parts store. Even if the MAF was bad it would cost you no where near that to replace it yourself.

When the mechanic called me to tell me the "news" he said he had "cleaned the diodes" and would drive it out after he finished the job he was on at the time. When he did it did not fix the trouble.

If he did that, then I assume it would be the same as using the MAF cleaner, right? I am NOT "mechanically inclined." In fact, if it requires more than a hammer or a screw driver I start sweating! lol

I found an air flow sensor in SC online for $98. It is a used part that supposedly came out of a totalled unit that had 9k miles on it. My X has 150K so I hate to spend tons on a small part. How hard is it to put this thing on?? I ain't got $700!! (If you have ever worked for a county sheriff's dept. you understand why! lol) The part was quoted as $604.34 + 2 hours labor (which we all know could mean anywhere from 5 minutes to ???.)

It's really easy. Unbolt the top of the air filter box and disconnect it from the intake tube. I don't know if it's a hose clamp or if it's screwed on. I think the MAF housing is screwed to the top of the air box and hose clamped to the intake tube. It also depends on whether the part you buy has the housing or is just the sensor. Once you have it in hand and can compare it to your truck parts, you'll see what I'm talking about. It's kinda hard to explain without pictures, and I have a second gen, so it's a little different. But it should require nothing more than a screwdriver, about 45 minutes and a little patience. I'm sure someone on here with a 1st gen can show you some pictures.

I'm liking the "only a screw driver" part!

So you are saying I should not have to fool with the wires at all, right?

Clean the Diode? Sounds like the stupid leading the stupid.

A diode does one thing, it limits electrical current flow in one direction. It works or it doesn't work, you can not fix a bad diode by cleaning it. Tell that moron if he uses this story one more time, I'm coming looking for him... Now, if that genius mechanic of yours knows how to identify a diode value and solder in a new diode, I'll eat my words, but fat chance that is how he "cleaned the diode". Sorry, but I can't stand misinformation.

I hope he checked the flux capacitor after he "cleaned" the diodes...wow...this mechanic is scaring me!!!

EDIT: Actually, I don't know what the gen one MAF looks like inside but the sensor wires sometimes look like little diodes so I think he was just using a term he thought fit.

Not sure how to take the "stupid leading the stupid" comment. I stated earlier that I am no mechanic, but you will never find me throwing down that kind of crap on here.

I hope he checked the flux capacitor after he "cleaned" the diodes...wow...this mechanic is scaring me!!!

EDIT: Actually, I don't know what the gen one MAF looks like inside but the sensor wires sometimes look like little diodes so I think he was just using a term he thought fit.

The MAF is just a filament(electrical resistor) and unless you drive without an air filter, and avoid driving through lakes, it does not get dirty enough to die, please, send me your old electronics, I'll clean them and save them as spares. Now, on the other hand, every single electrical connection plug on our engine wire harnesses are points of failure. Every single connector on my Xterra is packed with di-electic grease like they put on airplanes. I'll never have an electical problem from water or corrosion.
:wink-big:

Not sure how to take the "stupid leading the stupid" comment. I stated earlier that I am no mechanic, but you will never find me throwing down that kind of crap on here.

I apologize, just keep in mind I speak from experience. 2 hours ago, I was at my neighbors house, he is a retired engineer, fixing an electician's mistake on his new back deck lighting and fan setup he just had installed. Oh, and I did this with live circuits so I actually do know about electrical work.

And, as far as the stupid comments, I was reaching for the Forest Gump theme of, "Stupid is as Stupid does".

The MAF is just a filament(electrical resistor) and unless you drive without an air filter, and avoid driving through lakes, it does not get dirty enough to die, please, send me your old electronics, I'll clean them and save them as spares. Now, on the other hand, every single electrical connection plug on our engine wire harnesses are points of failure. Every single connector on my Xterra is packed with di-electic grease like they put on airplanes. I'll never have an electical problem from water or corrosion.
:wink-big:


Actually, I'm not sure of your point here. I think I was a little rough on the mechanic on retrospect, not really knowing what he was looking at, so I thought he saw something that looked like a diode and that's what he called it.

I'm an electrical engineer so I'm pretty sure I know a diode from a resistor. So IF I misread your insult about sending you my old electronics to clean I'll apologize in advance because it may not be what you meant.

Secondly, the MAF can get dirty enough to need cleaning. A dirty MAF definitely does affect performance. I tend to change my air filter too often so I have never had that issue.

Actually, I'm not sure of your point here. I think I was a little rough on the mechanic on retrospect, not really knowing what he was looking at, so I thought he saw something that looked like a diode and that's what he called it.

I'm an electrical engineer so I'm pretty sure I know a diode from a resistor. So IF I misread your insult about sending you my old electronics to clean I'll apologize in advance because it may not be what you meant.

Secondly, the MAF can get dirty enough to need cleaning. A dirty MAF definitely does affect performance. I tend to change my air filter too often so I have never had that issue.

Live and learn.... I learned years ago not to argue about anything. If I want someone's opinion, I give it to them. Sorry again, but, I do speak from personal experience.... And some of my relatives actually make me look stupid....:usuck:

Live and learn.... I learned years ago not to argue about anything. If I want someone's opinion, I give it to them. Sorry again, but, I do speak from personal experience.... And some of my relatives actually make me look stupid....:usuck:


I must be totally misunderstanding you because I have no idea of the point you are trying to get across here. Did I miss something? :)

I must be totally misunderstanding you because I have no idea of the point you are trying to get across here. Did I miss something? :)

This misinformation bit regarding black boxes (e.g. electronics)? I always speak up when I hear missinformation.

Here is another personal example. I've got this huge Samsung LCD on my fireplace wall that just up and died right out of warranty. Warranty was up, nobody knew nothing about the why it died. I'm stuck with what was a beautiful 5 thousand dollar picture, and still is... DID I GIVE UP????? NO!!!!

Do you want to know how I turn on this TV without spending a dime? Well, there are 48 individual high frequency inverter transformers that ignight the CCFL tubes. Did you know that if you can identify the one bad transformer of the 48 transformers, you can actually hit that transformer with a hair dryer, and the LCD will ignite? Obviously, I leave the back of this Samsung in storage, but the set is so thin that you really don't notice. I just feel sorry for anyone that reaches behind the LCD...:aufkopfhauen-big:

Well, to get this back on track, I think Uzedcarguy was given some good advice about cleaning the MAF but it looks like he found a used one and is gonna give that a try. Still, I would clean that one before he puts it in. Most Auto parts stores sell MAF cleaner so there is a reason for it. Do a search on the web about cleaning the MAF and you'll find just about every car forum out there has a thread on cleaning them because they do get dirty.

MAF Cleaner (http://the-auto-alley.amazonwebstore.com/MASS-AIR-FLOW-SENSOR-CLEANER-11/M/B000J19XSA.htm)

Turns out my wife has been putting back money for emergency situations and/or vacation this summer. Looks like I am not going to disney world. However, I am also not gonna give this guy $720! He will take less and I will give less. Even if I have to go buy the part and hand it to him. Thank you all for you comments and suggestions!

The MAF is just a filament(electrical resistor) and unless you drive without an air filter, and avoid driving through lakes, it does not get dirty enough to die, please,

Uuuhhh...uhoh.

When they changed the oil I had em change the air filter as well. It was kinda B A D... really bad.